CN101568303A - Sensor arrangement for home rehabilitation - Google Patents

Abstract

A sensor arrangement for home rehabilitation in particular after a stroke comprising at least two sensors. The sensors are attached to the user's body. Each sensor includes - a receiver for receiving a first signal being generated from a source outside the sensor 10 arrangement - a sensor processing unit processing the first signal and initializing a second signal upon reception of the first signal, the second signal including information regarding the identity of the sensor - a transmitter for transmitting the second signal to a central processing unit. 15 On receipt of the first and/or the second signal a time stamp is generated for each sensor for a determination of the location of each sensor relative to a source of the first signal trough comparison of the different time stamps.

Description

Sensor device for home rehabilitation

technical field

The present invention relates to systems and methods for rehabilitation and/or physical therapy for the treatment of neuromotor disorders such as stroke.

Background technique

Following a stroke, patients often suffer from disturbances in motor coordination. These disorders are the least understood but often the most debilitating with regard to functional recovery after brain injury. These coordination deficits manifest in the form of abnormal muscle synergy and result in limited and rigid movement patterns that are functionally disabling. A consequence of these limitations of muscle coordination is, for example, abnormal coupling between shoulder abduction and elbow flexion in the arm, which significantly reduces the space available to stroke survivors when lifting the weight of the damaged arm upward relative to gravity. Current neuromedical approaches to mitigate these abnormal synergies yield limited functional recovery. In the legs, abnormally synergistic manifestations lead to coupling between hip/knee extension and hip adduction. The result is a reduced ability to activate the hip abductors in the damaged leg during stance.

One of the most prominent disabilities suffered by stroke survivors is hemiparalysis of the upper extremities. Rehabilitation exercises have been shown to be effective in regaining motor control as long as the exercise is vigorous and the patient is guided during therapy.

When traditional therapy is provided in a hospital or rehabilitation center, the patient is usually observed between half-hour sessions once or twice a day. This was reduced to once or twice a week in outpatient treatment.

Current research suggests that motor exercises to improve a patient's coordination can be performed at home as part of a telerehabilitation solution. Technical solutions for unattended home stroke rehabilitation require the use of markers or sensors for capturing the posture of the patient during exercise. Pose acquisition via sensors is an attractive and heavily studied option.

The problem with this approach is that existing marker- or sensor-based tracking systems assume that the user is sufficiently skilled to place the chosen sensor at a specific location on the user's body, typically the hand, lower arm, and upper arm; thus Should achieve consistent results. Sensors are thus marked, colored or counted.

This assumption becomes unrealistic if the user is a stroke victim and is suffering from cognitive impairment. Conversely in this case, from one use to another, the exact position of the marker on the limb will be different because the user cannot place the marker on the body due to the user's loss of control over the movement of his arms, hands and/or fingers. Or the sensor is fixed to the exact same position. The necessary differentiation of the various sensors and assignments according to their placement is an additional burden on the stroke victim.

Contents of the invention

It is therefore an object of the present invention to minimize the amount of instructions for placing the sensor on the user's body and thereby facilitate the fastening process.

This object is solved by a sensor device for home rehabilitation, in particular after a stroke, comprising at least two sensors to be attached to the user's body, each sensor comprising: a receiver for receiving data from the A first signal generated by an external source of the sensor device; the sensor processing unit is configured to process the first signal and initialize a second signal after receiving the first signal, and the second signal includes information about the The information of the identification of sensor; Transmitter, be used for sending described second signal to central processing unit, wherein after receiving described first and/or described second signal, generate time mark (time stamp) to each sensor ) for determining the position of each sensor relative to the source of the first signal by comparison of different time stamps.

Hereby, the user is allowed to take any sensor and attach it to any desired body part, regardless of which sensor has to be placed on which part of the body.

After all the sensors have been placed on the different body parts, the distance of each sensor relative to the source of the first signal is calculated to determine the position of each sensor. Several different ways can be established to achieve this calculation.

The sensor device according to the first embodiment thus comprises a central processing unit comprising a time stamp generator, wherein a time stamp is generated in said central processing unit whenever a second signal has been received. A time stamp is then stored in the central processing unit together with information about the identity of the sensor.

In an alternative embodiment, each sensor comprises a time stamp generator, the time stamp generators of all sensors being synchronized with each other, wherein the time stamp is generated and stored in said sensor processing unit immediately after receipt of the first signal. In this embodiment, each sensor includes a time stamp generator. The risk of losing the second signal at the central processing unit is therefore insignificant, since the time stamp stored in the sensor processing unit can be interrogated whenever desired, and the interrogation can be repeated whenever desired.

The first and/or second signal may be an acoustic signal and/or a pulse signal and/or an optical signal. The first signal may be generated, for example, when the user extends his arms and claps his hands. Accordingly, an acoustic signal as well as a pulse signal are generated, which are detectable by the sensor, depending on whether the sensor is an acoustic sensor or a pulse sensor or both. It is also possible to use electronic or mechanical devices to trigger a sound or another signal. These devices may be included in a central processing unit.

Since the first signal should be the signal that enables the determination of the position of the sensors on the human body relative to each other, a sound signal or a pulse signal is advantageous today because, at two adjacent sensors, the first signal There is definitely a time lag between the detections of , and the sound waves or pulses travel relatively slowly so that they can be easily detected.

In the case of measuring the pulse generated by the user's clapping, the measurement can be made regardless of whether the user's arm is straight or not, because the pulse travels along the arm anyway.

In case an optical signal is used as the first signal, the difference between the two time stamps generated at two adjacent sensors after receiving the first signal will be very small, so that the measuring device must be very precise in order to Detect differences in time stamps. Currently, existing measurement devices that are able to detect measurable results even using optical signals are very expensive. In the future, it may make sense to use an optical signal as the first signal, if the cost of such a sensing device is no longer expensive.

On the other hand, it makes sense to use the light signal as the second signal, because the spectrum is very bright and easy to determine, and there is only a very short delay between the emission of the light signal from the sensor and its determination by the central processing unit, Said central processing unit is in one embodiment more precisely a photosensitive device provided in the central processing unit.

In one embodiment of the present invention, the first signal may be generated when the user extends his arms and claps his hands. Accordingly, an acoustic signal as well as a pulse signal are generated, which are detectable by the sensor, depending on whether the sensor is an acoustic sensor or a pulse sensor.

In order to ensure that the body part on which the sensor has been placed is aligned with the source of the first signal, the central processing unit may include communication means to issue instructions on how to proceed with the initialization of the sensor device and advise the user how to orient himself relative to the source of the first signal positioned to get the proper measurements. If the sensors are to be placed on the user's arm, the user may be instructed by the central processing unit to first place, for example, three sensors on his left arm, and then clap hands. After making a determination of the sensors on the left arm relative to each other, the central processing unit can instruct the user to place other sensors on his right arm, after which clap again, or instead of clapping, for example by saying "placement complete" or by pressing The button makes it possible thereby to generate a first signal from an external source indicating in any way that he has completed the placement of the sensor and is ready for the identification process of the sensor.

The external source may be an electronic or mechanical device to trigger a sound or another signal as the first signal. These devices may also be included in the central processing unit.

In order to avoid the generation of the second signal due to a signal from the environment that is not intentionally but only unintentionally generated, the sensor processing unit may compare the signal received by the receiver with the signal corresponding to the first signal stored in the sensor processing unit and wherein the sensor processing unit generates the second signal only if the signal received by the receiver matches the stored signal. This can be achieved by using a microphone as a receiver which registers, for example, the transmission of a sound wave, wherein the sensor processing unit can check whether the detected sound wave corresponds to a predetermined signal, or the source to other noises.

In one embodiment, each sensor may transmit differently after receiving said first signal, so that said central processing unit can simultaneously determine the identity of the sensor generating the second signal while receiving the second signal. Thus, each sensor can generate a second signal which at the same time shows its identity. This can be achieved eg if the second signal is an optical signal and each sensor emits with a different wavelength characterizing its identity. The light signal can be detected by a photosensitive device provided in the central processing unit. In the central processing unit, each wavelength can be dedicated to a specific sensor. Thus, by comparing the time stamps and thereby determining exactly which sensor the first signal reaches first, second or third, the time stamp of each sensor relative to the source of the first signal can be combined with the identity of the sensor that produced the second signal , are easily stored in the central processing unit. The same applies if the second signal is an acoustic signal, for example if a frequency specific to each sensor is selected.

The sensors may exchange their time stamps with each other in all-to-all communication to determine their position relative to the source of said first signal. Of course, it is also possible that, after determining the position relative to the source of the first signal, the sensors change their identities with respect to each other by completing a sorting process after exchanging their time stamps, so that thereafter their identities are the same as those at The order of placement on the user's body (eg, from wrist to shoulder) matches.

The sensors of the sensor device according to the invention can each be fixed on a carrier for fastening to the user's body, wherein said carrier can be formed in such a way that a minimum distance is ensured between two adjacent sensors, Due to the travel of the first signal, this minimum distance is necessary to obtain the measured difference of the time stamps.

A sensor device for home rehabilitation, particularly after a stroke, according to a presently preferred exemplary embodiment of the present invention will be described below with reference to FIGS. 1 and 2 , which fulfills the above objects and provides other beneficial features.

Those skilled in the art will readily appreciate that the description given herein with respect to the drawings is for illustration purposes only and is not intended to limit the scope of the invention.

Description of drawings

Figure 1 shows a sensor device according to the invention using the transfer of acoustic signals; and

Figure 2 shows an example of a sensor of such a device in which a time stamp is generated in the sensor.

Detailed ways

FIG. 1 shows a sensor device 1 especially for home rehabilitation after a stroke.

In order to minimize the amount of instructions for placing the sensors 1a, 1b, 1c on the user's arm 2, and thus facilitate the fastening process, the sensor device provides a sensor detection and identification mechanism, which calculates the sensor 1a, 1b, The distance of 1c relative to the source of the first signal, for example an acoustic signal, in the first implementation In an example, the first signal is generated by the user clapping hands 3 .

The sensor arrangement 1 comprises six separate sensors, of which three sensors 1a, 1b, 1c are attached to the user's left arm 2 and of which three (not shown) are placed on the user's right arm (also not shown).

Each sensor 1a, 1b, 1c is fixed on a carrier 4 which is fastened to the user's arm 2 one by one without following a particular sequence. In this embodiment, three equivalent sensors 1a, 1b, 1c are attached to the user's hand 3, lower and upper arms 3a and torso 3b. Set up the carriers 4 in such a way that there is a minimum distance d between each carrier 4 to ensure a minimum distance between two adjacent sensors 1a and 1b or 1b and 1c, since in FIG. For the travel of the first signal indicated by the curve at the left arm 2 of , this minimum distance is necessary to obtain the difference in the time stamps measured between the sensors 1a, 1b, 1c. The minimum distance d between two sensors 1a, 1b, 1c can be calculated as the rate of travel of the first signal proportional to the resolution of the time marker generator.

As shown in Figure 2, for the calculation of the distance of the sensor 1a, 1b, 1c relative to the user's hand 3, each sensor 1a, 1b, 1c includes: a receiver, for receiving the first signal; a sensor processing unit for processing the first signal after receiving the first signal, and initializing the second signal; and a transmitter for sending the second signal to the central processing unit 5 .

In this embodiment, each sensor 1a, 1b, 1c also includes a time stamp generator, such as a clock, wherein the clocks in all sensors 1a, 1b, 1c and sensors not shown are synchronized with each other, thereby allowing the passage of different time stamps In conjunction with the comparison of its identity, the position of each sensor 1a, 1b, 1c relative to the user's hand is determined.

The method for determining the sensor position works as follows:

Firstly, the user is invited by the central processing unit 5 to attach any three sensors 1a, 1b, 1c to his left arm, regardless of the sequence or identification of the sensors 1a, 1b, 1c. Thereafter, the user is instructed to extend both arms and clap 3 hands. Alternatively, the user may also not have to clap hands 3, but only indicate to the central processing unit 5 that he is finished with the placement process and that he is ready to proceed with determining the positions of the sensors 1a, 1b, 1c. Thereafter, the electronic or mechanical device within the central processing unit 5 invites the user to extend his arm 2 in the direction of the source of the first signal. Thereafter, the central processing unit 5 triggers a sound or a pulse or something appropriate as a first signal.

If the first signal is an impulsive signal (e.g. the user's clap 3), the step of extending the user's arm 2 in the direction of the source of the first signal can be ignored, since the impulsive signal travels within the user's arm 2 and therefore Flexing the arm will not change the measurements significantly.

Whenever the first signal is received by the receiver (here the microphone registering the transmitted sound waves) and sent to the sensor processing unit, the sensor processing unit compares the signal received by the microphone with a predetermined signal stored in the sensor processing unit . Only when the received signal corresponds to the stored signal in frequency spectrum, pulse height and/or width, the time stamp is generated by the time stamp generator and stored in the sensor processing unit to avoid errors caused by mismatching the predetermined signal , noise from the environment to generate time stamps.

Immediately after receiving the first signal and generating a time stamp, simultaneously or later, a second signal is generated by the sensor processing unit and transmitted by a transmitter (in this embodiment a radio device) To the central processing unit 5, the second signal comprises information about the identity of the sensors 1a, 1b, 1c and their corresponding time stamps.

The central processing unit 5 receives the time stamp and the identification of all sensors 1a, 1b, 1c. A comparison of different time stamps leads to information on which sensor 1a, 1b, 1c has been placed on which specific body part, e.g. sensor 1a with "logo 2" on the left hand, sensor 1b with "logo 1" on the lower left arm, And the sensor 1c with "logo 3" is on the upper left arm.

Once all sensors 1a, 1b, 1c have been identified, the user is informed that the determination of the sensors 1a, 1b, 1c on the left arm 2 has been completed and the same measurement is now to be carried out for the right arm. In the next step, all left arm sensors 1a, 1b, 1c will not participate in this measurement, since they have already been located.

Thus, the sensor device 1 enables the user to take any sensor 1a, 1b, 1c and attach it to any body part to be monitored (for example, the left arm 2), regardless of which sensor 1a, 1b, 1c has to be placed. In which part of the body and the sequence of the sensors 1a, 1b, 1c.

If the time stamps do not coincide, for example because the difference in measurement time between the sensors 1a, 1b, 1c is too long or too short, this is an indication that not all sensors 1a, 1b, 1c have been placed correctly or that the user is not connected to the source of the first signal Align properly. In this case, the user is asked to check again the sensor positioning and the positioning of his arm 2 relative to the central processing unit 5 before generating the first signal again, for example by clapping hands.

In an alternative embodiment (not shown), the central processing unit 5 comprises a central time stamp generator, wherein each time the second signal has been combined with information about the identity of the sensor 1a, 1b, 1c which emitted the second signal When sending from the sensor device 1 to the central processing unit 5 a time stamp is generated in the central processing unit 5 . In order to distinguish the sensor 1a, 1b, 1c that generates and transmits the second signal immediately after or simultaneously with receiving the second signal, in one embodiment, each sensor 1a, 1b, 1c receives Replying to the first signal in a very different way means that eg if the second signal generated by the sensors 1a, 1b, 1c is an optical signal, each sensor may emit at a different wavelength characterizing its identity. The light signal in this case is detected by a photosensitive device 6 provided in the central processing unit 5 and thereafter processed in the processing unit 5 . In the processing unit 5 each different wavelength is dedicated to a specific sensor 1a, 1b, 1c so that right after the signal is received it is possible for the correct sensor 1a, 1b, 1c to process the time stamp generated after reception. This makes it possible to determine exactly which sensor 1a, 1b, 1c the first signal reaches first, second or third on the left arm.

In another embodiment, the sensors 1a, 1b, 1c may exchange their time stamps with each other in full interchange communication in order to determine their position relative to the source of the first signal. Thereafter, each sensor 1a, 1b, 1c can undergo a separate sequencing process. By doing so, each sensor 1a, 1b, 1c knows its relative position from the sound source (here the central processing unit 5). Each sensor 1a, 1b, 1c knows which body part it supports, if information about sensor placement is available on the sensor 1a, 1b, 1c. This is important if a substantial part of the sensor data processing takes place on the sensors 1 a , 1 b , 1 c and not on the central processing unit 5 .

Of course, it is also possible, after determining the position relative to the source of the first signal, that the sensors 1a, 1b, 1c change their identifications among each other by completing a sorting process after exchanging their time stamps, so that thereafter their identifications are identical to those in the user Matches the order of placement on the body (for example, from wrist to shoulder).

Claims (14)

1. A sensor device (1) for home rehabilitation, especially after a stroke, comprising at least two sensors (1a, 1b, 1c) attached to the user's body, each sensor (1a, 1b, 1c )include: a receiver for receiving a first signal generated from a source external to said sensor device (1); a sensor processing unit configured to, upon receipt of said first signal, process said first signal and initialize a second signal comprising information about the identity of said sensor (1a, 1b, 1c); a transmitter for sending said second signal to a central processing unit (5), wherein a time is generated for each sensor (1a, 1b, 1c) after receiving said first and/or said second signal markers for determining the position of each sensor (1a, 1b, 1c) relative to the source of the first signal by comparison of different time markers. 2. The sensor device (1) according to claim 1, characterized in that said central processing unit (5) comprises a time stamp generator, and that whenever a second signal has been received at said central processing unit (5) Time stamps are generated, each time stamp being stored in the central processing unit (5) respectively together with information about the identity of the sensor (1a, 1b, 1c). 3. The sensor device (1) according to claim 1, characterized in that each sensor (1a, 1b, 1c) comprises a time stamp generator which is synchronized with each other, wherein immediately after receiving the first After the signal, a time stamp is generated and stored in the sensor processing unit. 4. The sensor device (1) according to any one of claims 1 to 3, characterized in that the first and/or second signal is an acoustic signal and/or a pulse signal and/or an optical signal. 5. The sensor device (1) according to any one of the preceding claims, characterized in that the sensor processing unit compares the signal received by the receiver with a predetermined signal corresponding to the first signal, wherein only If the signal received by the receiver matches the predetermined signal, the sensor processing unit generates the second signal. 6. The sensor device (1) according to any one of the preceding claims, characterized in that the central processing unit (5) comprises communication means for issuing instructions how to carry out the initialization of the sensor device (1). 7. The sensor device (1) according to any one of the preceding claims, characterized in that each sensor (1a, 1b, 1c) generates a different second signal after receiving said first signal, thereby simultaneously feeding said The central processing unit (5) indicates its identity. 8. The sensor device (1) according to any one of the preceding claims, characterized in that said sensors (1a, 1b, 1c) exchange their time stamps with each other in full interchange communication to determine their relative to said first signal The location of the source. 9. The sensor arrangement (1) according to claim 8, characterized in that the sensors (1a, 1b, 1c) complete the sorting process after exchanging their time stamps. 10. The sensor device (1) according to any one of the preceding claims, characterized in that the sensors (1a, 1b, 1c) comprise carriers formed such that a minimum distance between each other for performing the determination of their position is maintained . 11. A method for determining the position of a sensor on a user's limb by means of a sensor device (1) according to any one of the preceding claims, comprising the steps of: placing at least two sensors (1a, 1b, 1c) on one limb of the user's body, regardless of the order of said sensors (1a, 1b, 1c); extending a limb equipped with said sensor (1a, 1b, 1c) towards the source of said first signal; generating a first signal to be detected by said sensor (1a, 1b, 1c); Upon receipt of said first signal, said first signal is processed in said sensor processing unit and a second signal is initialized, said second signal comprising information about the identity of said sensor (1a, 1b, 1c) information; generating a time stamp by a time stamp generator if said first and/or second signal corresponds in spectrum, pulse and/or width to a pre-specified signal stored in said sensor processing unit; and Different time stamps are compared to assess the position of said sensor (1a, 1b, 1c) relative to the source of said first signal. 12. The method for determining the position of a sensor according to claim 11, characterized in that the first signal is generated when the user is invited to extend his arms (2) and clap his hands (3). 13. A method for determining the position of a sensor according to claim 11 or 12, characterized in that said time stamp is generated in each sensor. 14. Method for determining the position of a sensor according to claim 11 or 12, characterized in that the time stamp is generated in the sensor processing unit.

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